As a technique regarding an image projection apparatus that shifts the irradiation position of light emitted from a light emitting element by a movable mirror in sequence so as to draw an image on a display screen, the following techniques are known.
For example, an image projection apparatus is known that includes a plurality of light sources, a light scanning unit that scans a projection surface with light emitted from each of the light sources, a light detector that receives light from each of the light sources, and a control circuit that controls the plurality of light sources based on the output signal from the light detector and a video signal. The control circuit causes each of the light sources to emit light in one pixel section in a time division and to adjust the light emission intensity based on the output signal from a light detector in a light emission section of each of the light sources.
Also, an image projection apparatus is known that includes a light detection unit that detects the amount of light beams emitted from a light source, a light deflection unit that scans a projection surface with light beams reflected by a light reflection unit, a light-source output control unit that determines a drive current supplied to the light source, and an image processing unit that controls the light-source output control unit. The light-source output control unit corrects the drive current supplied to the light source such that the difference between the amount of light based on image information and the amount of light beams actually emitted based on the amount of light detected by the light detection unit. The image processing unit controls the light-source output control unit so as to replace a part of the drawing beams projected for drawing an image with control beams used for correcting the drive current.
A laser projector is known that includes a laser light source and a scanning unit that performs scanning with the laser light emitted from the laser light source, and that gives a drive current in accordance with an input image signal to the laser light source so as to cause the laser light source to emit laser light in order to project an image on a projection area. In the case where a first pixel and a second pixel are adjacent in the right and left direction, a drive current is changed to a threshold current value in a period of projecting a specific pixel such that the optical output of the laser light source becomes a predetermined magnitude at least at the end of the period of projecting the specific pixel, which is a first pixel.
The followings are reference documents.    [Document 1] Japanese Laid-open Patent Publication No. 2010-107615,    [Document 2] Japanese Laid-open Patent Publication No. 2010-175671, and    [Document 3] Japanese Laid-open Patent Publication No. 2011-39324.